Screw-on closure cap

ABSTRACT

A screw-on closure cap for closing the filling opening of a container or a tubular spout, the cap comprising relatively rotatable upper and threaded lower cap parts assembled together coaxially and having a resilient drive connection between them capable of transmitting a predetermined maximum torque between the upper and lower cap parts in the closing direction. The resilient drive connection comprises a bowed leaf spring whose arch is engaged in the interior of a pressed-up hand grip portion of the upper cap part, and whose two out-turned ends are resiliently engaged ratchetwise in depressions formed in the upper peripheral portion of the lower cap member. When limiting torque is reached the ends of the spring ride resiliently out of the recesses to allow the upper cap part to turn relatively to the lower cap part without further tightening the closure cap on the neck of the container or spout.

United States atent Blau et al.

[ 1 SCREW-ON CLOSURE CAP [72] Inventors: Werner Blau, Schneiderstrasse13-17, Langenfeld-lmmigrath (BRD); Theo Gerdes, D 4018 Langenfeld,Lortzingweg 9, both of Germany [22] Filed: Dec. 11, 1970 [21] Appl.N0.:97,194

[30] Foreign Application Priority Data Dec. 11, 1969 Germany ..P 19 62187.5

[52] US. Cl. ..220/39 R, 215/43 R, 215/49 [51] Int. Cl. ..B65d 41/04[58] Field of Search ..220/39 R; 215/49, 50, 55, 43 R [56] ReferencesCited UNITED STATES PATENTS 2,613,012 10/1952 Taylor et a1 ..220/39 R3,023,924 3/1962 Boyer ..220/39 R 51 May 30, 1972 Primary ExaminerM.Henson Wood, Jr. Assistant Examiner-John J. Love Attorney-Michael S.Striker [5 7] ABSTRACT A screwon closure cap for closing the fillingopening of a container or a tubular spout, the cap comprising relativelyrotatable upper and threaded lower cap parts assembled togethercoaxially and having a resilient drive connection between them capableof transmitting a predetermined maximum torque between the upper andlower cap parts in the closing direction. The resilient drive connectioncomprises a bowed leaf spring whose arch is engaged in the interior of apressedup hand grip portion of the upper cap part, and whose twoout-tumed ends are resiliently engaged ratchetwise in depressions formedin the upper peripheral portion of the lower cap member. When limitingtorque is reached the ends of the spring ride resiliently out of therecesses to allow the upper cap part to turn relatively to the lower cappart without further tightening the closure cap on the neck of thecontainer or spout.

3 Claims, 2 Drawing Figures SCREW-ON CLOSURE CAP The present inventionrelates to a closure cap which is adapted to be screwed on to the neckof a container or a tubular spout and to be tightened against a mouthaperture with the interposition of a seal.

In the case of such screw-on closures, it is a disadvantage that theymay be tightened too securely with respect to the periphery which is tobe sealed, so that it is difficult to open the closure by hand withoutusing considerable force; usually auxiliary means are required to openthe closure. Particularly when screw caps of this type are used forcontainers or tanks having oily contents or for motor vehicle fuels,they are exposed to such dirt in practice that it is usually impossibleto prevent slipping simply by cleaning before opening, and even if acloth is used it is hardly sufficient and usually a tool has to be usedto open the closure. Our copending application Ser. No. 94,410 describesa screw-on closure cap which cannot be tightened excessively withrespect to a container edge or spout part after a predetermined captorque or thread-tightness has been achieved. The characterizing featureof that application is that an upper cap part which transmits the rotarymovement has a lower threaded cap part inserted so as to be freelymovable therein and the connection therebetween is a spring element ofpredetermined tension so disposed that resiliently engaging projectionsproviding a mutual connection disengage ratchet-fashion on theattainment of a predetermined cap torque or thread-tightness in theclosure direction in order to give freely movable rotatability of theupper cap part in relation to the tightened lower threaded cap part.Consequently, a closure can be tightened only to a predetermined mutualthread-tightness pressure since forces originating from the reactionfrom such pressure and operative at the tightened lower threaded cappart cause the projections engaging resiliently from above in the formof spring lugs, cams or the like on the part providing the connection tothe upper cap part to be disengaged, since their spring tension is sopredetermined that on the attainment of a predetermined opposing forcefrom the tightened threaded cap part they disengage and the upper cappart can now only rotate freely since the internally interposedconnecting members can now only slip over the lower cap part in thetightened state without providing a coupling therewith. Said connectingmembers are also so constructed that when the upper cap part is turnedin the reverse direction for opening purposes they have the oppositeeffect and immediately restore the connection to the threaded cap part,for example by means of projecting members of such design directed inopposition to the direction of rotation for opening the cap so that theyengage in recesses in the lower threaded cap part so that the latter isautomatically entrained and turned back out of its closure position.

According to the present invention, which represents an Addition to theaforesaid copending application, a part engaging in the form of a bowedspring member in the upper rotary cap part and having ends which on bothsides are bent away outwardly against the lower threaded cap part isprovided between the two cap parts and engages resiliently in recessesat the periphery of the lower threaded cap part to provide a mutuallyresiliently flexible connection.

The main features of the principle according to the present applicationfor a Patent of Addition will be described with reference to anexemplified embodiment shown in the drawing wherein:

FIG. 1 is a central section through the closure according to theinvention, and

FIG. 2 is a partial section on the line II II in FIG. 1.

The Figures show an upper cap part 1 having a pressed-out hand grip part1 extending transversely over its outer surface,

and having a downwardly extended cap part 1" at the peripheral edge. Alower threaded cap part 2 is inserted within the upper cap part so as tobe freely movable and is retained by the rim part 1". A bowed member 3which engages in the form of a bridge between the two parts 1 and 2 isused as a connecting member and penetrates into the cavity of the grippart 1' and is adaptedto the sha e thereof and its ends extend downwardson both sides 3' an engage resiliently m depressions 2" provided at theperiphery 2' of the lower cap part 2. When the cap part 1/1 is turned inthe clockwise direction, i.e. the closure direction, this bowed memberconnecting part 3/3 in engagement with respect to the lower threaded cappart 2/2 causes the closure to be tightened as a unit afier the style ofa screwthread on a container neck or spout (not shown) with theinterposition of a washer beneath the flange edge 2 at the threaded cappart 2. When a predetermined cap torque or thread-tightness is achieveddepending upon the tension selected for the arm parts 3' engaging at 2",the ends of the arm parts 3' will disengage and pass over the recesses2" in the lower threaded cap part 2 so that the connection between thetwo cap parts 1 and 2 is broken and the closure cannot be tightened anymore. As a result of this ratchet-like disengagement, the top cap partcan now only rotate freely and cannot drive the lower cap part.

Depending upon requirements, the ends 3 drawn down on either side may beprovided with spring lugs 4 which are bent away laterally so as toproject and which engage in the recesses 2" in the edge flange 2' of thelower threaded cap part 2. The spring lugs 4 may also advantageouslyhave tongue parts 4 bent up in alignment with the direction of closingthe closure so that disengagement from the recesses 2" is possible withless resistance. In the opposite direction for opening the closure, theother side of the spring lugs 4 then engages in the recesses 2 onceagain immediately in the opposite way, as shown as 4 (FIG. 2), so thatthe lower threaded cap part 2 is entrained for opening purposes.

What we claim as our invention and desire to secure by Letters Patentis:

l. A screw-on closure cap comprising an upper cap part and a separatelower threaded cap part between which rotary movement is transmitted bymeans of resiliently engaging projections providing alimited-torque-transmitting connection between the said upper cap partand lower threaded cap part, the said lower cap part being unitarilymounted with the upper cap part so as to be rotatable therein, saidprojections auto matically disengaging when a predetermined cap torqueor thread-tightness is achieved, said projections comprising the twoends of a bowed member whose intermediate portion is engaged in theupper rotary cap part, said two ends being bent away outwardly and beingengaged resiliently in recesses at the periphery of the lower threadedcap part to provide a mutually resiliently flexible ratchet connectioncapable of transmitting tightening torque up to a limited value, saidprojections riding out of said recesses under the influence oftightening torque in excess of said limiting value.

2. A screw-on closure cap according to claim 1, in which said bowedmember fits in a hand grip part which is pressed out of the rotary uppercap part and extends transversely thereover, said two ends of the bowedmember which are bent down on both sides engaging with the lowerthreaded cap part via spring lugs which are bent out laterally so as toproject from the bowed member.

3. A screw-on closure cap according to claim 2, in which the laterallyprojecting spring lugs of the bowed member have tongue parts which aresituated in alignment in the direction of closing the closure and whichare bent upwards on one side.

1. A screw-on closure cap comprising an upper cap part and a separatelower threaded cap part between which rotary movement is transmitted bymeans of resiliently engaging projections providing alimited-torque-transmitting connection between the said upper cap partand lower threaded cap part, the said lower cap part being unitarilymounted with the upper cap part so as to be Rotatable therein, saidprojections automatically disengaging when a predetermined cap torque orthread-tightness is achieved, said projections comprising the two endsof a bowed member whose intermediate portion is engaged in the upperrotary cap part, said two ends being bent away outwardly and beingengaged resiliently in recesses at the periphery of the lower threadedcap part to provide a mutually resiliently flexible ratchet connectioncapable of transmitting tightening torque up to a limited value, saidprojections riding out of said recesses under the influence oftightening torque in excess of said limiting value.
 2. A screw-onclosure cap according to claim 1, in which said bowed member fits in ahand grip part which is pressed out of the rotary upper cap part andextends transversely thereover, said two ends of the bowed member whichare bent down on both sides engaging with the lower threaded cap partvia spring lugs which are bent out laterally so as to project from thebowed member.
 3. A screw-on closure cap according to claim 2, in whichthe laterally projecting spring lugs of the bowed member have tongueparts which are situated in alignment in the direction of closing theclosure and which are bent upwards on one side.